<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="vue.js"></script>
</head>

<body>
    <div id ="app">
        <input type="text" v-model="message"> <button v-on:click="handleBtnClick">添加</button>
        <p>您输入的是：{{message}}</p>
        <textarea v-model="sum"></textarea>
    </div>
<script>
    var app =new Vue({
         el:"#app",
        data:{
            message:"",
            sum:''
        },
    methods:{
        handleBtnClick:function(){
            this.sum +=this.message+'\n'
        }
    }
})
</script>
</body>
</html>